Basic PDFs#

Basic shapes are fundamental PDFs, with often well-known functional form. They are usually fully analytically implemented and often a thin wrapper around Distribution. Any missing shape can be easily wrapped using WrapDistribution.

Binned PDFs#

Binned PDFs extend the functionality of unbinned PDFs by providing more histogram-like features in addition to the basic unbinned PDFs. They interface with the Unified Histogram Interface (uhi) that is provided boost-histogram and especially Hist.


While polynomials are also basic PDFs, they convey mathematically a more special class of functions.

They constitute a sum of different degrees.

Kernel Density Estimations#

KDEs provide a means of non-parametric density estimation.

An extensive introduction and explanation can be found in Kernel Density Estimation.

Composed PDFs#

Composed PDFs build on top of others and provide sums, products and more.

Custom base class#

These base classes are used internally to build PDFs and can also be used to implement custom PDFs.

They offer more or less support and freedom.

Physics PDFs#

Physics PDFs are PDFs that are often used in high energy physics. They are in the zfit-physics package, which needs to be installed separately.